This invention relates to a burner arrangement, for example, for cooking units, wherein at least one gas burner is mounted in a supporting frame and the surrounding surface of the gas burner or gas burners is covered by a molded part of a brittle-friable material, such as glass, glass-ceramic or ceramic. Each gas burner extends through an opening in the molded part consisting of the brittle-friable material up to beyond the topside of the latter. Between the molded part and each gas burner, a long-term elastic junction and sealing device is provided with a junction and sealing element in contact firmly and in liquid-tight fashion with the marginal zone of the opening with at least one junction surface formed by the gas burner.
In gas ranges or bowl-shaped cooking units with a burner arrangement of this type, available on the market, the gas burners are fixedly mounted in the supporting frame or housing. A glass plate covering the surrounding surface of the gas burners is provided with an opening that is substantially larger than needed for the respective gas burner, for example with twice the diameter of the opening than the diameter of the respective gas burner. The thus-formed wide annular gap between the gas burner and the rim of the opening is covered with a ring-shaped sheet-metal collar which includes a sealing element only toward the opening rim of the glass plate but not toward the gas burner. Although a mechanical separation of the gas burner from the glass plate is thereby ensured, this manner of mounting of the gas burner within the glass plate has disadvantageous effects in practical use, especially with regard to cleaning. Thus, in these known devices, boiled-over matter can pass into the joint between the glass plate and the sheet-metal collar and run into the gap between the sheet-metal collar and the gas burner.
Therefore, cleaning of these conventional devices frequently requires at least partial disassembly.
It has been known from U.S. Pat. No. 5,046,487 to improve the seal of the burner with respect to the glass or glass-ceramic molding by making the opening of only such a size that it can accommodate the gas burner, and connecting the gas burner for sealing purposes along the opening rim firmly with the glass or glass-ceramic molding. Besides, the gas burner is attached to a crosspiece connected to the supporting frame. Such a mechanically rigid connection between a brittle-friable molded part, supporting frame, and gas burners, however, leads to the formation of distortions in the molded part under mechanical or thermal load on the cooking surfaces at the instant of stress. Depending on the structure, there may even be permanent distortions arising in the molded part. In either of the two cases, the risk of breakage of the molded part in a cooking unit or a gas range would be substantially increased.